having or showing distrust; "a man of distrustful nature"; "my experience...in other fields of law has made me distrustful of rules of thumb generally"- B.N.Cardozo; "vigilant and distrustful superintendence"- Thomas Jefferson

marked by practical hardheaded intelligence; "a smart businessman"; "an astute tenant always reads the small print in a lease"; "he was too shrewd to go along with them on a road that could lead only to their overthrow"